The Sim
The USS THERMOPYLAE NCC-74703-B is a Xiphos class very Heavy Galactic Survey Cruiser.
Sparta Station is one of Star Fleet's newest tactical starbases and supports the Thermopylae mission, specifically to investigate "strategically dangerous unknowns" ... to put it colloquially. The THERM, as she is affectionately known is sent by the Federation when "things" go bump in night" ... The Thermopylae usually "bumps" back.